The present invention is directed to a land surveying assist device, and in particular to a land surveying assist device which is capable of being aligned on-command by a remote transmitter situated at a distant random location.
Land surveying instruments are well-known to the prior art. One such typical instrument is a the odolite which is used in the field to obtain precise angular measurements for highway construction, industrial plant layout, tunnel construction and alignment, and other civil engineering work. Other known instruments, such as the Electronic Measuring Device (EDM) may be used to determine the distance between the instrument and any randomly located field point or survey station within its effective range. In working with the known instruments in land surveying operations, it is necessary for both the instrument station and the random field location to be manned by one or more members of the survey crew. In a known manner, the crew is able to manually align the instrument with the field location so that the various required angular and linear measurements may be made. It is apparent that this alignment procedure is time-consuming and requires the combined effort of several different individuals at different locations in the area to be surveyed.
Alignment on-command of the surveying assist device with one or more remote field locations or stations would significantly reduce the time required to perform the manual operations necessary for beam-path alignment. Such on-command alignments would also drastically reduce the costs of the survey operation by eliminating much of the manpower required to complete the survey.
The following United States patents illustrate the state of the art in surveying instruments; U.S. Pat. No. 3,653,774 (La Roche); U.S. Pat. No. 3,469,919 (Zellner); U.S. Pat. No. 4,107,530 (Brumfield et al); U.S. Pat. No. 4,425,043 (Van Rosmalen); U.S. Pat. No. 2,836,894 (Wagner); U.S. Pat. No. 3,580,687 (Hansen); U.S. Pat. No. 4,279,036 (Pfund); U.S. Pat. No. 4,466,189 (Tobin, Jr.); U.S. Pat. No. 4,457,621 (Harris et al); U.S. Pat. No. 4,470,698 (Green, Jr. et al); and U.S. Pat. No. 3,989,942 (Waddoups).
The LaRoche patent (U.S. Pat. No. 3,653,774) discloses a theodolite including a servo motor used for tracking a moving target. It does not disclose on-command alignment in a land surveying procedure.
The Zelner patent (U.S. Pat. No. 3,469,919) discloses an electronic surveying instrument including a laser beam projector coupled with an angled mirror to produce horizontal datum. The disclosed device also includes a receiver for receiving reflected beams to detect a datum plane and a pair of adjustable antennas which are movable to an elevation intersecting the datum plane and adjustable to insure proper spacing and elevation of the antennas.
The Wagner patent (U.S. Pat. No. 2,836,894) discloses a theodolite useful for tracking moving objects. It does not disclose a remotely controlled land surveying assist device for aligning on-command the same with a remote field location.
The Brunfield et al patent (U.S. Pat. No. 4,107,530), the Waddoups patent (U.S. Pat. No. 3,989,942), and the Van Rosmalen patent (U.S. Pat. No. 4,452,043) each generally disclose the use of radiation detectors to track radiating objects. These patents are not directed to land surveying instruments.
The Hansen patent (U.S. Pat. No. 3,580,687) discloses a surveying instrument which detects when it is misaligned, but it provides no means for on-command alignment.
The Pfund patent (U.S. Pat. No. 4,279,036) discloses a communication system with mobile vehicles including the use of a satellite; the Tobin, Jr., patent (U.S. Pat. No. 4,466,189) discloses an optical sensor used as a navigation aid for fixing and maintaining an accurate site on a target during rough water conditions; the Harris et al patent (U.S. Pat. No. 4,457,621) discloses a surveillance system including a laser range finder for use in conjunction with a passive surveillance scanner; and the Green, Jr., et al patent (U.S. Pat. No. 4,470,698) discloses a scanning and/or tracking mechanism for use as part of either an optical obstacle avoidance or target tracking airborne radar set. It is apparent that none of the last four mentioned patents disclose instruments useful for land surveying operations.
None of the above disclosures suggest a method or apparatus for land surveying which employs an assist device at a base line station for providing remote on-command alignment of surveying instruments located at one or more distant field locations.
It is an object of the present invention to provide an improved land surveying assist device which may be remotely aligned on-command with a distant field location to significantly reduce the time, labor, and cost involved in a land surveying operation. It is a further object of the invention to provide a method and apparatus for on-command alignment of instruments at one or more distant field locations utilizing a single land surveying assist device positioned at a base line station and remotely controlled from the field locations.